I, am totally new to arma 2 and dayz and stuff and i have the same problem but i have the game and expansions installed from steam. i don't know what you guys are talking about anyway haha but if anyone can help me, i would appreciate it it sais that some files like from a folder in the operation arrowhead forum are not signed by a key accepted by this server. i don't know what it is or even what it means, i tried uninstalling operation arrowhead but that won't let me start the game.. haha i'm a total noob to this.... but if anyone can help i would like to help i would greatly appreciate that.